1. Field of the Invention
The present invention relates to server borrowing apparatuses, methods of server borrowing, and computer program products for server borrowing for collectively allocating a server to a user group.
2. Description of the Related Art
In recent years, introduction of “grid computing” into server allocation is proposed to meet demands for, for example, improved server utilization, capability to handle a temporary increase in system load, and alleviation of negative impact of hardware failure. In a grid computing system in general, a server is shared by plural user groups and plural application programs run in parallel for respective user groups. In such a grid computing system where one server is shared by plural user groups, however, adjustment of resource allocation, such as allocation of CPU time, among user groups is required, and in addition, security has to be guaranteed for each of user groups.
To avoid these problems, a grid computing system employing a technique of server borrowing is proposed. The server borrowing is a technique to collectively lend out a server as a whole from one user group, which has sufficient servers to do away with one server, to another user group suffering from shortage of server capacity due to some problems such as a temporary load increase and hardware failure. For example, Hideki Yoshida, Nobuo Sakiyama, Toshibumi Seki, Tatsunori Kanai & Hideaki Hirayama, “Inter-Cluster Resource Borrowing through Grid Technology” (66th National Convention of Information Processing Society of Japan, March 2004) discloses a technique to borrow/lend various resources such as a server (node) among plural clusters using the grid technology. Here, “server borrowing” refers to one manner of resource borrowing which includes borrowing of any computational resources such as disks and networks besides the servers.
When such technique of server borrowing is employed, one server is borrowed as a whole between user groups and one user group utilizes the server at one time. Hence, the problems concerning resource allocation and security among different user groups do not arise as in the server sharing among plural user groups. An entity that performs the server borrowing is assumed mainly to be a cluster system that collectively manages the servers at the layer of middleware or operating systems (OSs). However, the entity of the server borrowing can be any system provided with plural servers such as a system configured as a combination of a load distribution apparatus and a WEB server, other than the cluster. Server borrowing may be realized so that the plural user groups mutually lend the server as described above. In addition, server borrowing can be realized so that only a dedicated lending group lends the server to other user groups.
In such server borrowing, a server which is lent to one user group may be lent to another user group afterwards. Then, the use of the server generally changes, which requires reinstallation of the OS and the application. Since the server borrowing is automatically realized according to the condition of server utilization, a human server manager cannot be expected to manually perform the reinstallation. Hence in the server borrowing, automatic installation of the OS and the application is required.
Generally, the term automatic installation refers to a manner of software installation that does not require manual manipulation by a manager. In the ordinary manual installation, setting information is manually provided by the manager, whereas in the automatic installation, a setting information file where such setting information is described is prepared, and the installation is performed automatically according to the contents of the setting information file.
The automatic installation which realized by such a rigid setting information file presupposes that the setting information can be previously determined. For example, even when there are plural options for one piece of setting information for one system, the automatic installation can be realized through preparation of plural setting information files and choosing one file as appropriate at each installation as far as each of the plural options for setting information is previously determinable.
In the reinstallation in the server borrowing, however, the setting information which is peculiar to each user group cannot be determined before it is known which user group is the lender and which user group is the borrower. Hence, the automatic installation cannot be realized according to the conventional manner where the rigid setting information files need to be previously prepared.
Some setting information is determined depending on the condition of the borrower user group. For example, it is usually the borrower side that sends request for installation setting related with a purpose of server use, e.g., a type of software to be used, a manner of software setting. On the other hand, some setting information is determined depending on the condition of the lender user group, which physically possesses the server. For example, it is usually the lender side that determines a setting request related with the server hardware and the server environment, e.g., a type of hardware to be used, and a manner of hardware setting. Further, some setting information is determined depending on the conditions of both the borrower and the lender. For example, security setting and network setting relate to the requests from both the lender group and the borrower group.
Hence, the setting information as a whole required for the reinstallation at the server borrowing varies according to the condition, i.e., depending on which server of which user group is to be lent to which group. Generally, it cannot be previously determined which server of which group is to be lent to which group, and the setting information for the installation cannot be prepared in advance. This means that in the server borrowing, the automatic installation cannot be realized in the conventional manner using the rigid setting information file.
Presently, a technique for automatic installation which solves the problems encountered in the server borrowing as described above is not proposed. Though Yoshida et al. mentioned above discloses interface expansion for the inter-cluster resource borrowing, they do not mention how to realize automatic installation.